Shiftless transmission



Patented Jan. 12, 1954 UNITED STATES PATENT OFFICE r 2,665,596 SHIFTLESSTRANSMISSION Harold E. Varble, Avenal, Calif.

Application July 13, 1951, Serial No. 236,523

9 Claims. (01. 74-756) This invention relates to a transmission forautomotive vehicles, boats, locomotives and for all uses where it isdesired to provide a varying ratio from a source of power to a drivenmember, that is, for such uses Where power is transmitted from an engineto a driven shaft at a speed which may be varied with that of theengine.

The primary object of this invention is to provide a simple assembly ofgears assembled as a unit in which no gear is ever shifted from itsassembled position, and from which can be obtained any successive gearratio, from reverse to over-drive, by the movement forward or backwardof a single control lever under the hand of the operator.

An additional object of the invention is to provide a gear transmissionfor connecting the drive shaft to the driven shaft through varying gearratios from over-drive to neutral and reverse without a clutch and thenecessity of shifting gears.

Another object is to provide a transmission having means for varyinggear ratios while maintaining the gears in mesh at all times, saidtransmission providing a novel braking means.

An additional object is to provide a highly flexible transmissionprovided with means for varyingthe gear ratio between the drive shaftand the driven shaft without unmeshing the meshed gears of saidtransmission.

Other objects will appear hereinafter throughout the specification.

In the drawings:

Figure 1 is a side elevation of the transmission, partly in section.

Figure 2 is a top plan view.

Figure 3 is a vertical sectional view taken on the line 33 of Figure 2and,

Figure 4 is an enlarged perspective view of the control mechanism.

This transmission is made up of three differentials mounted on parallelshafts and engaged in series, the first with the second, the second withthe third by the enmeshment of gears. This engagement is permanent andno gear is ever shifted. These three'diiferentials are somewhatdifferent in construction and each serves a different purpose.

The invention relates generally to a gear transmission having a driveshaft connected to the source of power, an intermediate shaft, and adriven shaft. Preferably, each of these shafts has mounted thereon adifferential means connected with gearing. This gearing is constantly inmesh as there is no shifting of any gear out .of engagement with anothergear. This transmission further includes gears mounted on each of theaforesaid shafts comprising one train of ears which is constantly drivenas long as the engine or other source of power is running. The othertrain of gears may be controlled so that one or more of the gears isdriven in one or the opposite direction or certain of the gears of thissecond train may be stopped, all at the will of the operator. Theinvention, however, does not preclude the use of one or more clutches,although it is preferred to dispense with the use of clutches.

Referring to the drawings, the numeral l is the drive shaft which ispreferably directly connected to the engine or other source of power.The invention does not preclude, however, the use of a clutch betweenthe source of power and the shaft l. A- clutch may be used at anysuitable place in the transmission. However, as stated above, thepreferred construction omits a clutch or any means for disengaging the gars hereinafter tobe described.

The numeral 2 indicate the intermediate shaft, and 3 is the driven shaftwhich latter may be connected to drive wheels or any other drivenmechanism such as a track laying tractor, a ships propeller,or anymachine.

The primary ear train comprises a side drive gear 5 keyed to the driveshaft l by the key 2. This gear drives the intermediate side ear 6 whichfreely turns on the shaft 2. Gear 6 meshes with the driven side gear Ifreely mounted on the driven shaft 3. This primary gear train isconstantly driven as long as the engine is running, but as stated above,a clutch may be interposed between the engine and the drive shaft i sothat this train of gearing would only be driven when the clutch isengaged.

Shafts l, 2 and 3 each mount differentials 8, 9 and I0 respectively.Driving side gears of differential 8 areindicated by the numerals II andI2. These gears are freely rotatable on shaft I. Gear II is providedwith beveled gear I3 and gear I2 is provided with beveled gear I4. Thesegears mesh with the pinion or spider gears l5 and I6 forming part ofdifferential 8. The pinion gears I5, I6 are mounted on short carriershafts that are fixed to rotate with the drive shaft I. It will be notedthat the side driving gears I l and I2 are of different size. Thesegears mesh with side driven gears I! and I8 respectively, which gearsare of different size and which are freely mounted on the intermediateshaft 2. It will be noted that the intermediate differential is mountedbetween and connects these gears to each other. The intermediatedifferential consists of a collar 9 fixed to gear 18, and this collarhas a bevel gear I!) fixed thereto. Gear l'l carries the spider gears 20and 2|, and gear 23 has a bevel gear, not shown. All three gears l7, itand 23 are loose on shaft 2, and the bevel gears of collar 9 and gear 23are connected by the spider gears 20 and 2 l on the gear I l.

Mounted for free rotation about the intermediate shaft 2 are the pinionor spider gears 28 and 2! as seen in Figure 3. Mounted on this shaft 2and also freely rotatable thereon is the intermediate gear 23. This gearis in mesh with side driven gear 24 which. like gear I, is free on theshaft 3.

Gears I and 24 are each provided with beveled gears 25 and 25respectively, each being fixed to its respective side driven gears andforming part of the driven differential 10. Also forming part of thisdifferential are pinion or spider gears 28 and 29. These latter gearsare mounted on a carrier that rotates with the shaft 3. Differential 8is keyed to shaft 1 by key 35, and differential H3 is keyed to shaft 3by key 3 l.

The control mechanism illustrated consists of a pair of pumps and afluid circuit for each gear I l and I2 with means for controlling theflow of fluid in the fluid circuit in which each pair of pumps islocated.

Referring to Figure 3, ear [2 is in meshed relationship with gear 32freely mounted on shaft 33 having suitable supporting pedestals 34 whichare bolted to the gear case 35 or any other suitable support. A link 36pivotally connects the pump gear 32 with the reciprocating shaft 37having pistons, not shown, in cylinders 38 and 39. These cylinders areconnected to each other by conduits 4!! and 41 so as to form a fluidcircuit, and the cylinders are supported on pedestals 42 and 43.

The rotation of the gear H is controlled by similar mechanism to thatdescribed above. This consists of a gear 44 also mountedfor freerotation on shaft 33 having a link 45 similar to link 36. Link 45pivotally connects reciprocating shaft 45 which operates pistons, notshown, in cylinders d! and 48 which latter are connected to each otherby conduits similar to conduits 4| and 42. Only one of these conduits 49is shown in Figure 2.

The control of rotary movement of the gears H and I2 is determined bythe flow of fluid in the circuit of each pair of pumps. Asdiagrammatically illustrated in Figure 4, this may be controlled by acontrol rod 50 which extends to within easy reach of the operator.Should the present mechanism form part of the automobile or truck drivethe rod 58 would extend by linkage to a point adjacent the steeringwheel. The opposite end of the rod 58 is provided with a pivot so as topivotally connect the same to a link 52, the opposite ends of which areprovided with plungers or pistons 53 and 54 that are connected to thelink 52 by pivots 55 and 56. In actual practice these pistons willextend down into and form a fluid tight engagement with the walls ofcylinders 5'! and 58 which form extensions of the pipes 4i and 5%respectively. For illustrative purposes, the pistons have been shown aslocated above the cylinders 51 and 58. Link 52 is pivotally connected at59 to a suitable stationary support 60 forming one of the sides of thegear case.

These pump systems may act as brakes or as the means for causing drivenshaft 3 to rotate in either direction or to remain stationary, eventhough shaft I is constantly driven.

Since gears II and 12 are mounted freely on the Shaft I but are in meshwith spider gears I5 and I6 which latter are driven by the engine shaft,if either gear II or I2 is held stationary, the power of the engine issent through the other gear. Each side gear H or I2 is provided with thebraking system indicated above. With this system which is illustrated inFigure 4, either gear H or 12 can be alternately slowed down or stoppedin its rotation. Should it be desired to stop the rotation of gear l2,the lever 50 is actuated by moving the same upward as seen in Figure I.This action will cause the piston 53 to stop the flow of fluid throughconduit 4| halting the movement of fluid in the circuit which includescylinders 38 and 39 by causing the differential on drive shaft 1 todrive gear II, gear H and through differential 9, gear 23, gear 24 andthrough the driven differential, driven shaft 3. This is the positionfor over-drive of the driven shaft 3.

Should the control rod 56 be pushed downwardly far enough, piston 54would stop the flow of fluid in pipe 49 thus stopping the rotation ofgear H and permitting through the driving differential, the driving ofgears I2, 18, 23 and 24, thus reversing the drive of shaft 3, that is,causing this shaft to rotate in the opposite direction.

The pairs of pumps are connected so as to pick up oil from the sump ofthe gear case as shown, or the oil may be in a closed circuit for eachof the pumps.

In place of the pistons and cylinders shown in Figure 4 any suitablevalve arrangement with linkage to the valves may be substituted. Thearrangement of pumps and the control shown form no part of the presentinvention xcept my invention broadly includes any control means forslowing down or stopping the rotation of either gear H or I2.

Through the differential construction shown in Figures 2 and 3 andassuming drive shaft 1 is continuously rotating during the operation ofthe engine or other power source, the driven shaft 3 may be rotated froma position of overdrive to its extreme position where the shaft 3 willrotate opposite its rotation when in overdrive pos tion. Moreover, thegears and differentials insure that the driven shaft 3 can be drivenfrom its over-drive position to any intermediate R. P. M. until theshaft 3 is in a neutral or non-rotating position by manipulation of thelever 50.

Moreover, this lever may be used to cause the pumps to act as brakes inthe shaft 3 in either direction.

claims. The drawings and specification are therefore to be understood asillustrative rather than limiting.

I claim:

1. Power transmission mechanism comprising a drive shaft, anintermediate shaft and a driven shaft, a primary gear train composed ofa plurality of gears in mesh with each other and in-- cluding a gearfixedly mounted on said drive s shaft and gears: freely-mounted on eachor the said other shafts; whereby alt or the gears or saidpi'iniarygear" train are continuously driven by said driveshaft; aseccndary geartraincom posed of a plurality of gears on'said' drive shaft and on saidintermediate shaft and at least; one gear on said driven shaft; saidsecondary gear train including a differential means fixed on said driveshaft drivingly connected tothe g'eals on said shaft or said secondarygear train and also including asecond differential means on saidintermediate shaft drivingly' conne'cted to the gears on said shaft; athird diriferential'means fixed on said driven shaft drivingly co to thegears on said driven shaftofboth s mary and secondary gear trains, meansfor se lectively controlling the" gearsof the se ondary said drive shaftwhereby ithel orward or reverse rotation is imparted to saiddriv'enshaft. i

'2. Pow r transmission mechanism comprising a drive shaft, anintermediate shaft and "a driven shaft, a primary gear train composed ora plural it'y of gears in mesh with each other and in-- cluding a gearmounted on each of the said shafts, means rigidly connecting said driveshaft with the gear mounted thereon whereby all of the gears of saidprimary gear train are con-- tinuously' driven by said drive shaft, asecondary gear train composed of aplurality of gears on Said drive shaftand said intermediate snort and at least one gear on said driven shaft,said secondary gear train including a differential means fixed on saiddrive shaft drivingly con nected to the-gears on said shaft of saidsecondary gear train and alsoincluding a second differential means onsaid intermediateshaft' drivingly connected to the gears on aid shaft,and a third differential means fixed on said driven shaft drivinglyconnected to the gears" on said driven shaft of both said primary andsecondary gear trains and means for selectively controlling therotationof the gears of said secondary gear train on said drive shaft.

3. Power transmission mechanismcomprising a drive shaft, an intermediateshaft and a driven shaft, a primary gear train composed of a pluralityof gears in mesh with each other andincluding a gear mounted on each ofthe said shafts, means rigidly connecting said drive shaft with the gearmounted thereon whereby all of the geal s of said primary gear train arecon tinuously driven by said drive shaft, a secondary gear traincomposed of a plurality of gears on said drive shaft and on saidintermediate shaft and at least one gear on said driven shaft, saidsecondary gear train including a differential means on said drive shaftdrivingly connected to the gears on said shaft of said secondary geartrain and also including a second differential means on saidintermediate shaft drivingly connected to the gears on said shaft, and athird differential means on said driven shaft drivingly connected to thegears on said driven shaft of both said primary and secondary geartrains and manually controlled means for selectively controlling therotational movements of the gears of said secondary gear train.

4. Power transmission mechanism comprising a drive shaft, anintermediate shaft and a driven shaft, a primary gear train composed ofa plurality of gears in mesh with each other and including a gearmounted on each of the said shafts, means rigidly connecting said driveshaft with the gear mounted thereon whereby all of the gents orsaidprimary gear train are con tinuously driven by said drive'sh'aft, asecondary gear" traincomposed of a plurality of scars on said driveshaft and said intermediate shaft and at least one gear on saiddrivenshaft'; and sec'orldary ear trainincluding a differential meansfixed on said drive shaft driyingly connected tomeears on said shaft-ofsaid secondary ear train and also including a second differential meanson said intermediate 'd-rivingly con'r'le'cted to the gears on said I da third differcnti al means fixed on said driven shaft driving-1ycon-nected to the gears o'n said driven shaft of both said primary andsec gear trains and manually controlled meansselectively controlling therotational movements of the gears of said secondary gear g on said driveshaft;

s Powe'r transmission mechanism comprising a drive-shaman intermediateshaft and a driven shaft, a primary ge train composed of a plura ty ofgears in n with each other and in: a gear mounted on eachcf' the saidshafts, meansrigidly connecting said drive shaft with the gear mountedthereon whereby a'llof the gears of said primary gear train arecontinuously driven by said drive shaft, a secondary gear train com osedof a plurality of gears on said drive shaft and said intermediate shaftand at least one gear on said driven shaft, said sec ondary gear trainincluding a differential moans fixed on said drive shaft drivingly'connected to the gears in said shaft of said secondary gear train andalso including a second differential means on saidintermediate shaftdrivingly con nected to the gears on said shaft, and a thirddifferential means fixed on said driven shaft drivingl-y connected tothe gears on said driven shaft of both said primary and secondary geartrains with the gear mounted thereon whereby all of the gears or saidprimary gear train are continuonsl driven, by said drive shaft, asecondary gear train composed of a plurality of gears on said driveshaft and said intermediate shaft and at least one gear on said drivenshaft, said secondary gear train including a differential means fixed onSaid drive shaft drivingl connected to the gears on said shaft of saidsecondary gear train and also including a second dilferential means onsaid intermediate shaft drivingly connected to the gears on said shaft,and a third differential means fixed on said driven shaft drivinglyconnected to the gears on said driven shaft of both said primary andsecondary gear trains and manually controlled hydraulic means forselectively controlling the rotational movements of the gears of saidsecondary gear train, said manually controlled hydraulic means includinga plurality of pairs of pumps, a fluid circuit for each pair of pumps,means drivlngly the rotation of the gear to which said pair of pumps isconnected.

7. Power transmission mechanism comprising a drive shaft, anintermediate shaft and a driven shaft, a primary gear train composed ofa plurality of gears in mesh with each other and including a gearmounted on each of the said shafts, means rigidly connecting said driveshaft with the gear mounted thereon whereby all of the gears of saidprimary gear train are continuously driven by said drive shaft, asecondary gear train composed of a plurality of gears on said driveshaft and said intermediate shaft and at least one gear on said drivenshaft, said secondary gear train including a differential means fixed onsaid drive shaft drivingly connected to the gears onsaid shaft of saidsecondary gear train and also including a second differential means onsaid intermediate shaft drivingly connected to the gears on said shaft,and a third differential means on said driven shaft drivingly connectedto the gears on said driven shaft of both said primary and secondarygear trains and manually controlled hydraulic means for selectivelycontrolling the rotational movements of the gears of said secondary geartrain on said drive shaft, said manually controlled hydraulic meansincluding a plurality of pairs ofpumps, a fluid circuit for each pair ofpumps, means drivingly connecting each pair of pumps to one of said lastnamed gears, and manually actuated means for simultaneously controllingthe movement of fluid in each of said fiuid circuits whereby to controlthe movement of each pair of pumps and the rotation of the gear to whichsaid pair of pumps is connected.

8. Power transmission mechanism comprising a drive shaft, anintermediate shaft and a driven shaft, a primary gear train composed ofa plurality of gears in mesh with each other and including a gearmounted on each of the said shafts, means rigidly connectin said driveshaft withv the gear mounted thereon whereby all of the gears of saidprimary gear train are continuously driven by said drive shaft, asecondary gear train composed of a plurality of gears on said driveshaft and said intermediate shaft and at least one gear on said drivenshaft, said secondary gear train including a differential means fixed onsaid drive shaft drivingly connected to the gears on said shaft of saidsecondary gear train and also including a second differential means onsaid intermediate shaft drivingly connected to the gears on said shaft,and a third differential means fixed on said driven shaft drivinglyconnected to the gears on said driven shaft of both said primary andsecondary gear trains, said plurality of gears on said intermediateshaft of said second gear train including a pair of loose gears on saidshaft between which is located said second differential means, a thirdgear on said intermediate shaft and means connecting said third gear andsecond differential means directly to each other whereby they rotate asone, said third gear being drivingly connected to the driven gear onsaid driven shaft of said second gear train.

9. Power transmission means comprising a drive shaft, an intermediateshaft and a driven shaft, a gear fixed to said drive shaft, a gearrotatable'on said intermediate shaft, meshing with said first-mentionedgear, a gear rotatably mounted on said driven shaft meshing with thesecond-mentioned gear, a first differential carrier fixedly mounted onsaid drive shaft and a second differential carrier fixedly mounted onsaid driven shaft and a third differential carrier rotatable on saidintermediate shaft, said differential carriers each having gearsrotatably mounted thereon, a pair of gears onsaid drive shaft, drivinglyconnected to the gears of said first differential, a pair of gears onsaid intermediate shaft drivingly connected to the gears on said thirddifferential and meshing with said first-mentioned pair of gears, afurther gear on said driven shaft, said further gear and saidthird-mentioned gear being drivingly connected to the gear on saidsecond differential and each meshing with one of the gears on saidsecondmentioned shaft, a fourth shaft, a pair of gears mounted thereonand meshing each with one of the first-mentioned pair of gears, meansfor selectively braking the gears of said last-mentioned pair wherebyforward and reverse rotation is imparted to said driven shaft, throughlocking of one side or the other of said first differential and causingsaid further gear to rotate in either of two directions at speedsdifferent from that of said third gear.

HAROLD E. VARBLE.

References Cited in the file of this patent UNITED STATES PATENTS(Addition to No. 718,202)

